Please post your question in the correct forum. Your graphics problem has nothing to do with CPUs or overclocking.
you can post in pc gaming forum.
with ur full system specscomputers are a second home
NVIDIA GeForce
toxict51
To run GTA4 at a high resolution and with lots of detail, you should have a 512MB video card based on a decent GPU (Geforce 8800+, Radeon HD 4850+), and a quad-core (or a hyper-threaded dual-core) CPU. Super PIII | Unlocked ES Tualatin @ 1.8GHz (150x12, 1.65v, 512K L2)
2GB PC2700 | 500GB | Radeon x1950Pro | Apollo Pro 266T | Win 7 Pro